A new wide-guage sauropod track site from the Late Cretaceous .....

["Yasmani Ceballos Izquierdo" <yceballos@uci.cu>]

J.G.R. Riga & J.O. Calvo, 2009. A new wide-guage sauropod track site from the 
Late Cretaceous of Mendoza, Neuquen Basin, Argentina. Palaeontology 
52(3):631-640. ABSTRACT. Agua del Choique is a new Late Cretaceous sauropod 
track site from Mendoza Province, Neuquén Basin, Argentina. It is situated in 
the Loncoche Formation, late Campanian - early Maastrichthian in age, and is 
one of the youngest sauropod tracks site recorded in the world. Agua del 
Choique represents a lake setting and river-dominated delta deposits, and 
comprises at least 160 well-preserved tracks, located on a calcareous sandstone 
bed. A new ichnotaxon, Titanopodus  mendozensis ichnogen. et ichnosp. nov., is 
erected for the footprints of this track site. Titanopodus  mendozensis 
exhibits the following association of features: (1) wide-gauge trackway (manus 
and pes trackway ratios of 18-22 and 26-31 per cent respectively), (2) 
pronounced heteropody (manus-pes area ratio of 1:3), (3) outer limits of 
trackway defined, in some cases, by the manus tracks, and (4) manus impression 
with an asymmetrical crescent contour and acuminate external border. 
Titanopodus  mendozensis is an excellent case study of the wide-gauge style of 
locomotion produced by Late Cretaceous derived titanosaurs that have no 
impression of manual phalanges. These features, and the fossil record from the 
Loncoche Formation, suggest that the trackmakers were, probably, middle size 
saltasaurine or aeolosaurine20titanosaurs (14-16 m long).